Welcome to SUnits
SUnits is a Units Calculator.
Current version: 6.3
Written by: saiba
License: GPLv2
Installation
No installation required, single exe file. Download SUnits (Console version)
NOTE: Sometimes downloaded file name does not have ".exe" extension. In that case, please append ".exe" to the downloaded file name to make it an executable.
Features
- Uses matlab like command prompt.
- Useful for converting units in "complex" form, like N/m -> lbf/in or N*m*s/rad -> lbf*in*s/deg.
- Fractional powers for units, eg: time = (2*m / g_acc)^1|2
- Addition of physical quantities, eg: distance = 2*km + (2*km/hr)*5*min + 1/2*(1.3*m/s^2)*(5*min)^2
- User defined units.
- User defined functions.
- GUI is in DFL
Examples
> ~ <- this character starts a comment
> distance = 23.5 * m
distance = 23.5 m
> time = 4.9 * s
time = 4.9 s
> speed = distance / time
speed = 4.79592 m / s
> speed_in_miles_per_hour = speed > mi/hr
speed_in_miles_per_hour = 10.7282
> temp_centigrade = 37.0 * dC
temp_centigrade = 37 dC
> temp_fahrenheit = dc2df(temp_centigrade)
temp_fahrenheit = 98.6 dF
> func time_period(len) { len :: m; 2 * pi * (len / g_acc)^1|2; }
function added: time_period(len)
> time_period(6*m)
ans = 4.91468 s
> ~ Base conversion, from base 10 to 16
> printInBase(16, 123.456)
@123.456_10 = @7b.74bc6a_16
ans = 123.456
> ~ Base conversion, from base 16 to 10
> @a2b3b4d_16
ans = 1.70605e+08
BNF
translation-unit : statements
statements : ( statement EOS )+
EOS : ";" | "," | EOF
End-of-statement. If a statement is followed by ";", its value is
not echo-ed. EOF is end-of-file
statement : cmd | assign_expr | func_def | unit_def
For available 'cmd' see at the end.
assign_expr : (var ( "=" | ":=" ) )? dim_chk_expr
Assignment expression. Operator ":=" ensures that the variable "var"
is not defined earlier.
dim_chk_expr : conv_expr ( (":" | "::") mul_expr)?
Dimension check expression,
Operator ":" Checks if conv_expr is dimensionless or conv_expr and
mul_expr have same dimensions,
Operator "::" Checks if conv_expr conv_expr and mul_expr have
strictly same dimensions,
Returns conv_expr. Useful to ensure dimensions of intermediate steps.
conv_expr : add_expr ( (">" | "->" | "<" | "<-") add_expr)*
Conversion expression,
">" and "<" are not comparision operators, but conversion operators
defined as follows:
a > b = a/b
a < b = b/a
"<-" and "->" are same as "<" and ">", but prints pretty equation.
add_expr : mul_expr ( ("+" | "-") mul_expr)*
mul_expr : pow_expr ( ("*" | "/") pow_expr)*
unary_expr : ("-" | "+" | "#" | "$")? pow_expr
Operator "#" is non-dimensionalizing operator, strips all dimensions
and makes the expression dimensionless. Operator "$" makes the
magnitude unity.
pow_expr : pri_expr ("^" exp_expr)?
pri_expr : real_no | real_any_base | var | func_call | paran_expr
func_call : var ( "(" func_call_args ")" )+
function var is called repeatedly for all sets of
arguments. Returned value is the return value from the
last call.
func_call_args : ( dim_chk_expr ( "," dim_chk_expr )* )*
paran_expr : "(" conv_expr ")"
exp_expr : unary_int ( "|" unary_int )?
Currently only integer or integer ratios in p|q form are allowed
in exponents. Floating point values are not allowed in exponents,
as it makes comparing dimensions harder.
For example 2.3^4.5 is not allowed, it can be written as 2.3^9|2
Please note that "|" used in exponent not "/".
unary_int : ("-" | "+")? int_no
real_any_base : "@" float_any_base ( "_" int_no )?
real_any_base is an float literal, value is specified by
float_any_base after "@" in base specified after "_".
float_any_base : [0-9a-zA-Z]+ ("." [0-9a-zA-Z]+)?
Upto base 36 can be represented using above alphabets.
int_no : [0-9]+
func_def : ( "func" | "funcdef" ) var "(" func_def_args ")"
"{" statements "}" ( description )?
Function call always returns the last assign_expr value.
Using "funcdef" ensures that the "var" is not defined earlier.
func_def_args : ( var ( "," var )* )?
unit_def : "newunit" var ( description )?
Create new fundamental unit
var : C identifier
var_name : C identifier
real_no : C floating point number
description : any string not containing statement_end
cmd : described below
cmd:
====
delete var : deletes a variable var from memory
precision int : set display precision of floats, default 6.
catagory cat : set catagory for subsequently defined variables
defof : show definition and value of a variable
cls : clear screen
about : print info about the program
doc : print documentation
examples : print some examples
Note:
-----
o Line comment starts with '~' until end of line.
o If file sunits.units exist in current working directory,
it is read on start up.